(function($, window) {
    
        var template = '<div id="{{id}}" class="mui-slider mui-preview-image mui-fullscreen"><div class="mui-preview-header">{{header}}</div><div class="mui-slider-group"></div><div class="mui-preview-footer mui-hidden">{{footer}}</div><div class="mui-preview-loading"><span class="mui-spinner mui-spinner-white"></span></div></div>';
        var itemTemplate = '<div class="mui-slider-item mui-zoom-wrapper {{className}}"><div class="mui-zoom-scroller"><img src="{{src}}" data-preview-lazyload="{{lazyload}}" style="{{style}}" class="mui-zoom"></div></div>';
        var defaultGroupName = '__DEFAULT';
        var div = document.createElement('div');
        var imgId = 0;
        var PreviewImage = function(options) {
            this.options = $.extend(true, {
                id: '__MUI_PREVIEWIMAGE',
                zoom: true,
                header: '<span class="mui-preview-indicator"></span>',
                footer: ''
            }, options || {});
            this.init();
            this.initEvent();
        };
        var proto = PreviewImage.prototype;
        proto.init = function() {
            var options = this.options;
            var el = document.getElementById(this.options.id);
            if (!el) {
                div.innerHTML = template.replace(/\{\{id\}\}/g, this.options.id).replace('{{header}}', options.header).replace('{{footer}}', options.footer);
                document.body.appendChild(div.firstElementChild);
                el = document.getElementById(this.options.id);
            }
    
            this.element = el;
            this.scroller = this.element.querySelector($.classSelector('.slider-group'));
            this.indicator = this.element.querySelector($.classSelector('.preview-indicator'));
            this.loader = this.element.querySelector($.classSelector('.preview-loading'));
            if (options.footer) {
                this.element.querySelector($.classSelector('.preview-footer')).classList.remove($.className('hidden'));
            }
            this.addImages();
        };
        proto.initEvent = function() {
            var self = this;
            $(document.body).on('tap', 'img[data-preview-src]', function() {
                if (self.isAnimationing()) {
                    return false;
                }
                self.open(this);
                return false;
            });
            var laterClose = null;
            var laterCloseEvent = function() {
                !laterClose && (laterClose = $.later(function() {
                    self.isInAnimation = true;
                    self.loader.removeEventListener('tap', laterCloseEvent);
                    self.scroller.removeEventListener('tap', laterCloseEvent);
                    self.close();
                }, 300));
            };
            this.scroller.addEventListener('doubletap', function() {
                if (laterClose) {
                    laterClose.cancel();
                    laterClose = null;
                }
            });
            this.element.addEventListener('webkitAnimationEnd', function() {
                if (self.element.classList.contains($.className('preview-out'))) { //close
                    self.element.style.display = 'none';
                    self.element.classList.remove($.className('preview-out'));
                    laterClose = null;
                } else { //open
                    self.loader.addEventListener('tap', laterCloseEvent);
                    self.scroller.addEventListener('tap', laterCloseEvent);
                }
                self.isInAnimation = false;
            });
            this.element.addEventListener('slide', function(e) {
                if (self.options.zoom) {
                    var lastZoomerEl = self.element.querySelector('.mui-zoom-wrapper:nth-child(' + (self.lastIndex + 1) + ')');
                    if (lastZoomerEl) {
                        $(lastZoomerEl).zoom().setZoom(1);
                    }
                }
                var slideNumber = e.detail.slideNumber;
                self.lastIndex = slideNumber;
                self.indicator && (self.indicator.innerText = (slideNumber + 1) + '/' + self.currentGroup.length);
                self._loadItem(slideNumber);
    
            });
        };
        proto.isAnimationing = function() {
            if (this.isInAnimation) {
                return true;
            }
            this.isInAnimation = true;
            return false;
        };
        proto.addImages = function(group, index) {
            this.groups = {};
            var imgs = [];
            if (group) {
                if (group === defaultGroupName) {
                    imgs = document.querySelectorAll("img[data-preview-src]:not([data-preview-group])");
                } else {
                    imgs = document.querySelectorAll("img[data-preview-src][data-preview-group='" + group + "']");
                }
            } else {
                imgs = document.querySelectorAll("img[data-preview-src]");
            }
            if (imgs.length) {
                for (var i = 0, len = imgs.length; i < len; i++) {
                    this.addImage(imgs[i]);
                }
            }
        };
        proto.addImage = function(img) {
            var group = img.getAttribute('data-preview-group');
            group = group || defaultGroupName;
            if (!this.groups[group]) {
                this.groups[group] = [];
            }
            var src = img.getAttribute('src');
            if (img.__mui_img_data && img.__mui_img_data.src === src) { //已缓存且图片未变化
                this.groups[group].push(img.__mui_img_data);
            } else {
                var lazyload = img.getAttribute('data-preview-src');
                if (!lazyload) {
                    lazyload = src;
                }
                var imgObj = {
                    src: src,
                    lazyload: src === lazyload ? '' : lazyload,
                    loaded: src === lazyload ? true : false,
                    sWidth: 0,
                    sHeight: 0,
                    sTop: 0,
                    sLeft: 0,
                    sScale: 1,
                    el: img
                };
                this.groups[group].push(imgObj);
                img.__mui_img_data = imgObj;
            }
        };
    
    
        proto.empty = function() {
            this.scroller.innerHTML = '';
        };
        proto._initImgData = function(itemData, imgEl) {
            if (!itemData.sWidth) {
                var img = itemData.el;
                itemData.sWidth = img.offsetWidth;
                itemData.sHeight = img.offsetHeight;
                var offset = $.offset(img);
                itemData.sTop = offset.top;
                itemData.sLeft = offset.left;
                itemData.sScale = Math.max(itemData.sWidth / window.innerWidth, itemData.sHeight / window.innerHeight);
            }
            imgEl.style.webkitTransform = 'translate3d(0,0,0) scale(' + itemData.sScale + ')';
        };
    
        proto._getScale = function(from, to) {
            var scaleX = from.width / to.width;
            var scaleY = from.height / to.height;
            var scale = 1;
            if (scaleX <= scaleY) {
                scale = from.height / (to.height * scaleX);
            } else {
                scale = from.width / (to.width * scaleY);
            }
            return scale;
        };
        proto._imgTransitionEnd = function(e) {
            var img = e.target;
            img.classList.remove($.className('transitioning'));
            img.removeEventListener('webkitTransitionEnd', this._imgTransitionEnd.bind(this));
        };
        proto._loadItem = function(index, isOpening) { //TODO 暂时仅支持img
            var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (index + 1) + ')'));
            var itemData = this.currentGroup[index];
            var imgEl = itemEl.querySelector('img');
            this._initImgData(itemData, imgEl);
            if (isOpening) {
                var posi = this._getPosition(itemData);
                imgEl.style.webkitTransitionDuration = '0ms';
                imgEl.style.webkitTransform = 'translate3d(' + posi.x + 'px,' + posi.y + 'px,0) scale(' + itemData.sScale + ')';
                imgEl.offsetHeight;
            }
            if (!itemData.loaded && imgEl.getAttribute('data-preview-lazyload')) {
                var self = this;
                self.loader.classList.add($.className('active'));
                //移动位置动画
                imgEl.style.webkitTransitionDuration = '0.5s';
                imgEl.addEventListener('webkitTransitionEnd', self._imgTransitionEnd.bind(self));
                imgEl.style.webkitTransform = 'translate3d(0,0,0) scale(' + itemData.sScale + ')';
                this.loadImage(imgEl, function() {
                    itemData.loaded = true;
                    imgEl.src = itemData.lazyload;
                    self._initZoom(itemEl, this.width, this.height);
                    imgEl.classList.add($.className('transitioning'));
                    imgEl.addEventListener('webkitTransitionEnd', self._imgTransitionEnd.bind(self));
                    imgEl.setAttribute('style', '');
                    imgEl.offsetHeight;
                    self.loader.classList.remove($.className('active'));
                });
            } else {
                itemData.lazyload && (imgEl.src = itemData.lazyload);
                this._initZoom(itemEl, imgEl.width, imgEl.height);
                imgEl.classList.add($.className('transitioning'));
                imgEl.addEventListener('webkitTransitionEnd', this._imgTransitionEnd.bind(this));
                imgEl.setAttribute('style', '');
                imgEl.offsetHeight;
            }
            this._preloadItem(index + 1);
            this._preloadItem(index - 1);
        };
        proto._preloadItem = function(index) {
            var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (index + 1) + ')'));
            if (itemEl) {
                var itemData = this.currentGroup[index];
                if (!itemData.sWidth) {
                    var imgEl = itemEl.querySelector('img');
                    this._initImgData(itemData, imgEl);
                }
            }
        };
        proto._initZoom = function(zoomWrapperEl, zoomerWidth, zoomerHeight) {
            if (!this.options.zoom) {
                return;
            }
            if (zoomWrapperEl.getAttribute('data-zoomer')) {
                return;
            }
            var zoomEl = zoomWrapperEl.querySelector($.classSelector('.zoom'));
            if (zoomEl.tagName === 'IMG') {
                var self = this;
                var maxZoom = self._getScale({
                    width: zoomWrapperEl.offsetWidth,
                    height: zoomWrapperEl.offsetHeight
                }, {
                    width: zoomerWidth,
                    height: zoomerHeight
                });
                $(zoomWrapperEl).zoom({
                    maxZoom: Math.max(maxZoom, 1)
                });
            } else {
                $(zoomWrapperEl).zoom();
            }
        };
        proto.loadImage = function(imgEl, callback) {
            var onReady = function() {
                callback && callback.call(this);
            };
            var img = new Image();
            img.onload = onReady;
            img.onerror = onReady;
            img.src = imgEl.getAttribute('data-preview-lazyload');
        };
        proto.getRangeByIndex = function(index, length) {
            return {
                from: 0,
                to: length - 1
            };
            //		var from = Math.max(index - 1, 0);
            //		var to = Math.min(index + 1, length);
            //		if (index === length - 1) {
            //			from = Math.max(length - 3, 0);
            //			to = length - 1;
            //		}
            //		if (index === 0) {
            //			from = 0;
            //			to = Math.min(2, length - 1);
            //		}
            //		return {
            //			from: from,
            //			to: to
            //		};
        };
    
        proto._getPosition = function(itemData) {
            var sLeft = itemData.sLeft - window.pageXOffset;
            var sTop = itemData.sTop - window.pageYOffset;
            var left = (window.innerWidth - itemData.sWidth) / 2;
            var top = (window.innerHeight - itemData.sHeight) / 2;
            return {
                left: sLeft,
                top: sTop,
                x: sLeft - left,
                y: sTop - top
            };
        };
        proto.refresh = function(index, groupArray) {
            this.currentGroup = groupArray;
            //重新生成slider
            var length = groupArray.length;
            var itemHtml = [];
            var currentRange = this.getRangeByIndex(index, length);
            var from = currentRange.from;
            var to = currentRange.to + 1;
            var currentIndex = index;
            var className = '';
            var itemStr = '';
            var wWidth = window.innerWidth;
            var wHeight = window.innerHeight;
            for (var i = 0; from < to; from++, i++) {
                var itemData = groupArray[from];
                var style = '';
                if (itemData.sWidth) {
                    style = '-webkit-transform:translate3d(0,0,0) scale(' + itemData.sScale + ');transform:translate3d(0,0,0) scale(' + itemData.sScale + ')';
                }
                itemStr = itemTemplate.replace('{{src}}', itemData.src).replace('{{lazyload}}', itemData.lazyload).replace('{{style}}', style);
                if (from === index) {
                    currentIndex = i;
                    className = $.className('active');
                } else {
                    className = '';
                }
                itemHtml.push(itemStr.replace('{{className}}', className));
            }
            this.scroller.innerHTML = itemHtml.join('');
            this.element.style.display = 'block';
            this.element.classList.add($.className('preview-in'));
            this.lastIndex = currentIndex;
            this.element.offsetHeight;
            $(this.element).slider().gotoItem(currentIndex, 0);
            this.indicator && (this.indicator.innerText = (currentIndex + 1) + '/' + this.currentGroup.length);
            this._loadItem(currentIndex, true);
        };
        proto.openByGroup = function(index, group) {
            index = Math.min(Math.max(0, index), this.groups[group].length - 1);
            this.refresh(index, this.groups[group]);
        };
        proto.open = function(index, group) {
            if (this.element.classList.contains($.className('preview-in'))) {
                return;
            }
            if (typeof index === "number") {
                group = group || defaultGroupName;
                this.addImages(group, index); //刷新当前group
                this.openByGroup(index, group);
            } else {
                group = index.getAttribute('data-preview-group');
                group = group || defaultGroupName;
                this.addImages(group, index); //刷新当前group
                this.openByGroup(this.groups[group].indexOf(index.__mui_img_data), group);
            }
        };
        proto.close = function(index, group) {
            this.element.classList.remove($.className('preview-in'));
            this.element.classList.add($.className('preview-out'));
            var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (this.lastIndex + 1) + ')'));
            var imgEl = itemEl.querySelector('img');
            if (imgEl) {
                imgEl.classList.add($.className('transitioning'));
                var itemData = this.currentGroup[this.lastIndex];
                var posi = this._getPosition(itemData);
                var sLeft = posi.left;
                var sTop = posi.top;
                if (sTop > window.innerHeight || sLeft > window.innerWidth || sTop < 0 || sLeft < 0) { //out viewport
                    imgEl.style.opacity = 0;
                    imgEl.style.webkitTransitionDuration = '0.5s';
                    imgEl.style.webkitTransform = 'scale(' + itemData.sScale + ')';
                } else {
                    if (this.options.zoom) {
                        $(imgEl.parentNode.parentNode).zoom().toggleZoom(0);
                    }
                    imgEl.style.webkitTransitionDuration = '0.5s';
                    imgEl.style.webkitTransform = 'translate3d(' + posi.x + 'px,' + posi.y + 'px,0) scale(' + itemData.sScale + ')';
                }
            }
            var zoomers = this.element.querySelectorAll($.classSelector('.zoom-wrapper'));
            for (var i = 0, len = zoomers.length; i < len; i++) {
                $(zoomers[i]).zoom().destory();
            }
            //		$(this.element).slider().destory();
            //		this.empty();
        };
        proto.isShown = function() {
            return this.element.classList.contains($.className('preview-in'));
        };
    
        var previewImageApi = null;
        $.previewImage = function(options) {
            if (!previewImageApi) {
                previewImageApi = new PreviewImage(options);
            }
            return previewImageApi;
        };
        $.getPreviewImage = function() {
            return previewImageApi;
        }
    
    })(mui, window);